Most obviously, the return type of the system calls send, recv, etc. are given as ssize_t, but the bindings in this library appear to use CInt, which is usually not the same on a 64-bit platform. I believe this works only because the same registers are used by the calling convention regardless of integer size, so the Haskell side simply reads only the low 32 bits, and single messages of 2 GiB size probably would not work anyway.
The reason this came up is that I am writing an extension to this library to send and receive file descriptors with unix domain sockets, which requires me to bind the sendmsg and recvmsg system calls. I used CSsize for the return type and found that the type of System.Socket.Unsafe.tryWaitRetryLoop is incompatible with that – it require CInt to be used.
Some places in the code also appear to use CInt in place of socklen_t, but that does appear to always be the same, according to a cursory search.
Most obviously, the return type of the system calls
send,recv, etc. are given asssize_t, but the bindings in this library appear to useCInt, which is usually not the same on a 64-bit platform. I believe this works only because the same registers are used by the calling convention regardless of integer size, so the Haskell side simply reads only the low 32 bits, and single messages of 2 GiB size probably would not work anyway.The reason this came up is that I am writing an extension to this library to send and receive file descriptors with unix domain sockets, which requires me to bind the
sendmsgandrecvmsgsystem calls. I usedCSsizefor the return type and found that the type ofSystem.Socket.Unsafe.tryWaitRetryLoopis incompatible with that – it requireCIntto be used.Some places in the code also appear to use
CIntin place ofsocklen_t, but that does appear to always be the same, according to a cursory search.